1. Field of the Invention
The present invention relates to an apparatus for for efficiently and ecologically satisfactorily disposing of organic waste materials which include organic solids susceptible to combustion, and including household and organic industrial wastes. More particularly, the invention relates to a method of employing the heat developed and exhausted during the operation of an internal combustion engine for the purpose of efficiently disposing of organic waste materials of the type described.
2. Brief Description of the Prior Art
Social concern for the manner in which industry, as well as family units, dispose of organic wastes generated from time to time by the industry or in the household has intensified in recent times as concern for the contamination and pollution of man's environment has deepened. The materials which may be discarded, or which must be necessarily gotten rid of in some way, or reclaimed, include both organic and inorganic substances, and various proposals have been advanced to alter, or to completely eliminate, time worn methods of disposal, so that harmful by-products of the disposal process are not generated and released to the natural environment, and where possible, conservation of valuable constituents of the waste material is achieved.
In one area of concern relating to the subject of disposal of wastes, household wastes in the form of human excrement, as well as organic garbage wastes, have received attention. Although in the past, chemical treatments which rendered the waste materials innocuous to humans, followed by discharge to natural streams or to the air, were considered acceptable methods of disposition, such methods are no longer considered generally satisfactorily where the effluent products of the treatment are deleterious to natural flora and fauna other than man. Moreover, the efficiencies of chemical treatments have, in many cases, become inadequate, and new methods of disposal of these types of organic waste have been sought.
The problem of satisfactorily disposing of household wastes, such as sewage and garbage, has been an especially serious one where the wastes are generated on such vehicles or conveyances as ships, boats, house trailers or mobile homes, Here, no permanent sewage system connected to mains or the like can generally be provided, and a portable, efficient disposal system is needed. On some marine vessels, the waste is simply thrown overboard in flagrant disregard of clean water considerations. In some cases, septic type holding systems have been employed, with chemical treatment of the sewage being effected so that relatively innocuous masses of material may ultimately be discharged when the vessel or vehicle has reached a point in its sailings or travel where such discharge can be legally and safely effected. In other cases, attempts have been made to convert the sewage and garbage thermally to products which are non-polluting with respect to the atmosphere, or to bodies of water. As illustrative of efforts which have been made in the direction of thermal conversion of organic waste materials developed during the occupation and use of vehicles and vessels, the systems described in U.S. Pat. No. 3,616,913 to Reid, in U.S. Pat. No. 3,622,511 to Pizzo, and in U.S. Pat. No. 3,673,614 to Claunch may be mentioned.
The Reid system described in U.S. Pat. No. 3,616,913 constitutes the culmination of an effort extending over several years by Reid to use heat in the exhaust gases from an internal combustion engine to purify the liquid portion of sewage and kitchen garbage so as to permit the water content thereof to be conserved, and convert any solids entrained in the liquid to innocuous materials which may be discharged with the exhaust gases. In this most recent of several patents issued to Reid in this field, a boiler is provided into which the liquid content from the waste materials is first directed for purposes of evaporation as a result of heat exchange with the hot gases exhausted from an internal combustion engine. The residue, which contains some organic material, continues to accumulate in the boiler over an extended period of time. To the end of cleaning the boiler by elimination of this organic residue, means is provided for permitting air to be drawn into the boiler periodically, wherein, in conjunction with the very high temperatures prevailing therein, the accumulated solid organic material coating the boiler is burned. The fine ash which then remains is swept out of the boiler through a conduit, and is merged with the exhaust gases from the engine and vented to the atmosphere.
The main solid material constituting a major portion of the human wastes or garbage generated in the course of use of the vehicle to which the Reid system is attached is passed initially into a septic tank, where the material, before, or concurrently with, the removal of the liquids therefrom for passage to the described boiler, is treated with chemicals by conventional procedure, and is rendered innocuous by such treatment. The solid material which remains after such chemical treatment is periodically cleaned out of the septic tank at times and locations where such solids removal is legal and convenient.
In Pizzo U.S. Pat. No. 3,622,511, a compact mechanical system is described which is employed for treating sewage, and is suitable for use on small ships. Here, the sewage is first macerated and then sent to an evaporator where a submersible burner drives off the liquid content of the sewage and concentrates the solids. The vaporized liquids are passed to a condenser and after condensation, can be separated and utilized in several optional ways. The concentrated solids from the evaporator, present as a pumpable sludge, are pumped to a sludge incinerator device where the solids are burned with a suitable fuel which reduces the solid organic material to ash and carbon dioxide. The effluent from the incinerator is passed through a water spray to remove ash particles prior to exhausting the effluent gases to the atmosphere. The fuel for the evaporator submerged burner, and also for the incinerator, can be diesel oil of the type provided on the vessel where the system is used.